<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>文档对象模型</title>
  </head>
  <body>
    <button>文档中的按钮1</button>
    <button>文档中的按钮2</button>
  </body>
  <script>
    // 修改文档标题
    document.title = "DOM";
    const btn = document.querySelector('button')
    const btn1 = document.querySelectorAll("button")
    console.log(btn)
     console.log(btn1)
     
  </script>
  </script>
</html>
